Method for improving polar code performance using local pre-transformation

Abstract

An encoder using local pre-transformation is provided. According to an embodiment, the encoder may include a bit splitting unit configured to generate a specific information signal and remaining information signals by splitting an input signal, a pre-transform unit configured to generate connection signals by performing, in parallel, local pre-transformation, based on each of the remaining information signals, and a polar transform unit configured to generate an output signal by performing polar transformation, based on the specific information signal and the connection signals.

What is claimed is: 
     
         1 . An encoder using local pre-transformation, the encoder comprising:
 a bit splitting unit configured to generate a specific information signal and remaining information signals by splitting an input signal;   a pre-transform unit configured to generate connection signals by performing, in parallel, local pre-transformation, based on each of the remaining information signals; and   a polar transform unit configured to generate an output signal by performing polar transformation, based on the specific information signal and the connection signals.   
     
     
         2 . The encoder of  claim 1 , wherein
 the polar transform unit is further configured to   perform the polar transformation, based on the specific information signal and non-consecutive information bits of the connection signals, and   to obtain the output signal from a result of the polar transformation.   
     
     
         3 . The encoder of  claim 1 , wherein
 a number of consecutive information bits of the connection signals is limited based on a size of each connection signal.   
     
     
         4 . The encoder of  claim 1 , wherein
 the pre-transform unit comprises local pre-transform units, and   each of the local pre-transform units   is configured to generate the connection signal by performing the local pre-transformation using an upper-triangular matrix, based on a corresponding remaining information signal.   
     
     
         5 . The encoder of  claim 1 , wherein
 the pre-transform unit comprises local pre-transform units, and   each of the local pre-transform units   is configured to generate a pre-transform input signal by adding one or more frozen bits to a corresponding remaining information signal and   to generate the connection signal by performing the local pre-transformation on the pre-transform input signal.   
     
     
         6 . The encoder of  claim 5 , wherein,
 as the one or more frozen bits are added to the corresponding remaining information signal, the connection signal comprises non- consecutive information bits.   
     
     
         7 . The encoder of  claim 5 , wherein
 each of the local pre-transform units   is further configured to assign the corresponding remaining information signal to one or more elements of the pre-transform input signal indicated by a corresponding information index set and   to assign the one or more frozen bits to one or more remaining elements of the pre-transform input signal.   
     
     
         8 . The encoder of  claim 1 , wherein
 the polar transform unit is further configured to   generate a polar transform input signal comprising the specific information signal, the connection signals, and one or more frozen bits and   to generate the output signal by performing polar transformation on the polar transform input signal.   
     
     
         9 . The encoder of  claim 8 , wherein
 the polar transform unit is further configured to   assign the specific information signal to one or more elements of the polar transform input signal indicated by a corresponding information index set,   assign a corresponding connection signal to one or more elements of the polar transform input signal indicated by a connection index set, and   assign the one or more frozen bits to one or more remaining elements of the polar transform input signal.   
     
     
         10 . The encoder of  claim 9 , wherein
 the information index set and the connection index set comprise, from among total indices of the polar transform input signal, indices having high channel reliability and having a corresponding row-weight of a polar transformation matrix greater than or equal to a predetermined threshold value.   
     
     
         11 . An encoding method using local pre-transformation, the encoding method comprising:
 generating a specific information signal and remaining information signals by splitting an input signal;   generating connection signals by performing, in parallel, local pre- transformation, based on each of the remaining information signals; and   generating an output signal by performing polar transformation, based on the specific information signal and the connection signals.   
     
     
         12 . The encoding method of  claim 11 , wherein
 the generating of the output signal comprises:   performing the polar transformation, based on the specific information signal and non-consecutive information bits of the connection signals; and   obtaining the output signal from a result of the polar transformation.   
     
     
         13 . The encoding method of  claim 11 , wherein
 a number of consecutive information bits of the connection signals is limited based on a size of each connection signal.   
     
     
         14 . The encoding method of  claim 11 , wherein
 the generating of the connection signals comprises   obtaining the connection signals by performing, in parallel, the local pre- transformation using an upper-triangular matrix, based on each of the remaining information signals.   
     
     
         15 . The encoding method of  claim 11 , wherein
 the generating of the connection signals comprises:   generating pre-transform input signals by adding one or more frozen bits to the remaining information signals, respectively; and   generating the connection signals by performing, in parallel, the local pre-transformation on each of the pre-transform input signals.   
     
     
         16 . The encoding method of  claim 15 , wherein,
 as the one or more frozen bits are added to the remaining information signals, respectively, the connection signals comprise non-consecutive information bits, respectively.   
     
     
         17 . The encoding method of  claim 15 , wherein
 the generating of the pre-transform input signals comprises   assigning a corresponding remaining information signal to one or more elements of a pre-transform input signal indicated by a corresponding information index set and   assigning the one or more frozen bits to one or more remaining elements of the pre-transform input signal.   
     
     
         18 . The encoding method of  claim 11 , wherein
 the generating of the output signal comprises   generating a polar transform input signal comprising the specific information signal, the connection signals, and one or more frozen bits and   generating the output signal by performing polar transformation on the polar transform input signal.   
     
     
         19 . The encoding method of  claim 18 , wherein
 the generating of the polar transform input signal comprises:   assigning the specific information signal to one or more elements of the polar transform input signal indicated by a corresponding information index set;   assigning a corresponding connection signal to one or more elements of the polar transform input signal indicated by a connection index set; and   assigning the one or more frozen bits to one or more remaining elements of the polar transform input signal.   
     
     
         20 . A decoding method comprising:
 receiving an input signal; and   generating an output signal corresponding to the input signal by sequentially searching for decoding paths with respect to the input signal and selecting a final decoding path from among the decoding paths,   wherein a number of the decoding paths does not exceed a predetermined number, and   the input signal corresponds to a codeword encoded based on parallel local pre-transformation and polar transformation.